Although infectious diseases like smallpox used to occasionally spread from the dead to the living, it's unlikely that corpses can trigger infectious disease epidemics if people died of trauma, doctors say.

"Corpses themselves -- other than their ghoulish aspect or their psychological implications -- are not per se hazardous to people," said Dr. William Schaffner, chairman of preventive medicine at Vanderbilt University Medical Center in Nashville, Tenn.

Dr. James Wilson, who directs the National Infectious Disease Forecast Center, agreed.

"This is a myth that occasionally appears even in [World Health Organization] statements," Wilson said.

The main health concern associated with corpses is that bacteria from their decomposing gastrointestinal tracts can seep into the drinking water supply, in which case they can spread E. coli, norovirus or other gastrointestinal bugs, Schaffner said. But this would be a concern even without mass casualties because natural disasters tend to disrupt waste disposal, allowing sewage to get into drinking water.

"It's paradoxical," Schaffner said. "This is a disaster caused by wind and water, but you don't have safe water."

Norovirus is especially likely because only a low dose is needed to get someone sick, he said. And since norovirus is characterized by vomiting and diarrhea, it causes dehydration, which is especially troublesome when the water is unsafe to drink.

Fortunately, the World Health Organization is practiced at making sure victims get water with electrolytes and giving them intravenous fluids to prevent dehydration, said Dr. Ethan Leonard, an infectious disease expert at University Hospitals Case Medical Center in Cleveland.

Other potential health concerns after a disaster like this include mosquito-borne illnesses, such as dengue fever; tetanus exposure, from people stepping on sharp unseen objects as they wade through floodwaters; and transmission of respiratory illnesses like the flu as people huddle in shelters, Wilson said.